Magnesia carbon brick (MgO-C brick) is the premier unburned carbon composite refractory for modern steelmaking vessels, specifically engineered for BOF furnace walls, EAF t spots, and steel ladle slag lines.
By combining high-purity fused magnesia (MgO ≥97%) with premium flake graphite (Carbon 10–18%), Highland Refractory provides a lining solution that offers exceptional slag repellency and thermal shock stability at temperatures up to 1800°C.
Our MgO-C series features advanced antioxidant systems (Al, Mg, or B4C) to prevent graphite oxidation, extending campaign life by up to 25% compared to standard basic bricks.
Alumina Magnesia Carbon Bricks (AMC Bricks) are high-performance carbon-bonded refractory bricks engineered for the most demanding positions in steelmaking equipment—ladle slag lines, converter walls, and secondary refining furnaces. Manufactured from high-purity fused alumina, fused magnesia, and flake graphite, AMC bricks combine the slag resistance of magnesia, the thermal shock stability of carbon, and the high-temperature strength of alumina through in-situ spinel (MgAl₂O₄) formation during firing. Highland Refractory supplies Alumina Magnesia Carbon Bricks with Al₂O₃ 70–80% and MgO 8–15% to steel mills in 60+ countries.
Magnesia carbon brick is a non-burning carbon composite refractory with high melting point basic oxide magnesium oxide (melting point 2800℃) and high melting point carbon material which is difficult to be penetrated by slag as raw materials, adding various non-oxide additives and combining with carbon binder. As a kind of composite refractory material, magnesia carbon brick effectively utilizes the strong slag resistance of magnesia and the high thermal conductivity and low expansion of carbon to compensate for the poor spalling resistance of magnesia.
Alumina Magnesia Carbon Bricks (AMC Bricks) are high-performance carbon-bonded refractory bricks engineered for the most demanding positions in steelmaking equipment—ladle slag lines, converter walls, and secondary refining furnaces. Manufactured from high-purity fused alumina, fused magnesia, and flake graphite, AMC bricks combine the slag resistance of magnesia, the thermal shock stability of carbon, and the high-temperature strength of alumina through in-situ spinel (MgAl₂O₄) formation during firing. Highland Refractory supplies Alumina Magnesia Carbon Bricks with Al₂O₃ 70–80% and MgO 8–15% to steel mills in 60+ countries.
Magnesia carbon brick is a non-burning carbon composite refractory with high melting point basic oxide magnesium oxide (melting point 2800℃) and high melting point carbon material which is difficult to be penetrated by slag as raw materials, adding various non-oxide additives and combining with carbon binder. As a kind of composite refractory material, magnesia carbon brick effectively utilizes the strong slag resistance of magnesia and the high thermal conductivity and low expansion of carbon to compensate for the poor spalling resistance of magnesia.
Table of Contents (Technical Navigation)
The metallurgical performance of a magnesia carbon brick is governed by the synergy between the high melting point of periclase (MgO, ~2800°C) and the non-wetting properties of graphite. Unlike pure magnesia bricks, which suffer from slag penetration and spalling, the graphite phase in MgO-C bricks creates a physical barrier that prevents aggressive basic slags from wicking into the brick matrix.
Highland Refractory utilizes a high-pressure (2000-ton) molding process and specialized phenolic resin binders to achieve apparent porosities ≤4.0%. This structural density is critical for steel plants looking to reduce the "cost-per-ton" of steel by minimizing refractory-sourced inclusions and reducing relining frequency.
Sourcing the correct magnesia carbon brick requires matching the carbon content and magnesia purity to the specific wear zone of the furnace. Below are the standard specifications for our global export series.
| Property | Grade MT-10 | Grade MT-14 (Slag Line) | Grade MT-18 (Premium) |
|---|---|---|---|
| MgO Content (%) | ≥ 82% | ≥ 80% | ≥ 76% |
| Fixed Carbon (%) | 10 ± 1% | 14 ± 1% | 18 ± 1% |
| Bulk Density (g/cm³) | ≥ 2.85 | ≥ 2.88 | ≥ 2.90 |
| CCS after drying (MPa) | ≥ 35 | ≥ 30 | ≥ 25 |
| Antioxidant System | Al / Mg | Al-Mg-Si | B4C + Al-Mg |
The fatal weakness of any mag carbon brick is the oxidation of its graphite phase. When graphite burns away, the brick becomes porous and structurally fragile. To combat this, Highland incorporates a multi-tier antioxidant strategy:
Modern steelmaking vessels are "Zonal Lined" to optimize both performance and cost. A single furnace may utilize three different grades of magnesia carbon brick:
A critical sourcing concern for foreign buyers is hydration. Magnesia (MgO) reacts with moisture in the air to form Mg(OH)2, which causes the brick to expand and crack during storage. Highland Refractory solves this through:
• Vacuum Sealing: Every pallet is vacuum-wrapped in multi-layer moisture-proof plastic.
• Resin Encapsulation: Our manufacturing process includes a specialized resin coating on the fused magnesia grains to block moisture contact.
• Anti-Hydration Testing: Every batch is tested in a high-humidity chamber to ensure a shelf-life of ≥6 months in humid environments like Southeast Asia or Middle East ports.
Sourcing certified MgO-C bricks with factory-direct pricing and technical layout support. 2h response on quotes.
The main raw materials of magnesia carbon bricks include fused magnesia or sintered magnesia, flake graphite, organic bonds and antioxidants.
High melting point basic oxide magnesium oxide (melting point 2800℃)
In the harsh environments of steelmaking and metallurgical processes—where extreme temperatures (up to 1800℃), aggressive slag erosion, and frequent thermal shocks dominate—refractory materials are the unsung heroes that ensure operational stability, reduce downtime, and control costs. Among these, magnesia carbon bricks (MgO-C bricks) stand out as the gold standard for critical applications like basic oxygen furnaces (BOF), electric arc furnaces (EAF), and ladle slag lines. Engineered by combining high-purity magnesia (MgO) with graphite and advanced carbon binders, these unburned carbon composite refractories leverage the complementary strengths of their components to outperform traditional refractories in durability, corrosion resistance, and thermal stability. This comprehensive guide unpacks everything industrial buyers, steel mill engineers, and metallurgy professionals need to know about magnesia carbon bricks—from their composition and properties to applications, technical specifications, and why they’re the preferred choice for high-demand metallurgical environments.
Magnesia carbon brick is a non-burning carbon composite refractory with high melting point basic oxide magnesium oxide (melting point 2800℃) and high melting point carbon material which is difficult to be penetrated by slag as raw materials, adding various non-oxide additives and combining with carbon binder. As a kind of composite refractory material, magnesia carbon brick effectively utilizes the strong slag resistance of magnesia and the high thermal conductivity and low expansion of carbon to compensate for the poor spalling resistance of magnesia.
Magnesia bricks are basic refractory products whose performance depends on more than MgO content alone. The manufacturing route and bond system influence the brick’s structure, thermal response, resistance to slag penetration, oxidation sensitivity and handling requirements. The main routes considered in industrial procurement are sintered magnesia brick, fused magnesia brick and unburned or chemical-bonded magnesia brick. This guide explains how these routes differ and what information a buyer should confirm before ordering. It does not replace the MZ-91, MZ-95 and MZ-97 technical data page. For grade-specific MgO, density, porosity, CCS and RUL values, see the MZ grade and performance guide.
